The Navy yesterday said it will conduct an environmental impact statement analysis of increased training around Hawai'i and its effect on marine mammals.

The comprehensive review will be made as the Navy prepares to "enhance" training and testing in the Hawai'i Range Complex, which encompasses offshore, near-shore and onshore areas around the major islands of Hawai'i.

"The proposal, which is necessary as global defense technology advances, includes an increased occurrence of fleet and large-scale training exercises, upgraded (missile) tracking ranges and test facilities, and enhanced capabilities to test and train with new, emerging technologies, vehicles and systems," the Navy said in a news release.

One alternative being considered by the Navy would include three aircraft-carrier strike groups training at the same time, increasing the tempo of training exercises, and research at the Pacific Missile Range Facility on directed energy programs involving lasers.

The environmental report will include an analysis of sonar and other effects on marine mammals — a contentious topic that saw environmentalists sue the Navy over mid-frequency sonar use during this summer's Rim of the Pacific war games off Hawai'i.

As part of the review process, the Navy will hold public meetings on Maui, O'ahu, the Big Island and Kaua'i in mid-September to gather input on what environmental issues need to be addressed.

A draft environmental impact statement is expected to be completed by May 2007, and a final document is scheduled for early 2008.

More Navy ships are being based in the Pacific since the Cold War ended and major threats have shifted to this region.

With the proliferation of foreign diesel submarines, Adm. Gary Roughead, who commands U.S. Pacific Fleet, made anti-submarine warfare the fleet's top maritime war-fighting priority.

Roughead ordered that all aircraft carriers and expeditionary strike groups deploying from the West Coast conduct several days of anti-submarine warfare training near Hawai'i.

From January to March, three strike groups, each with a half-dozen or more ships and submarines, rotated through for the training, which relies heavily on sonar.

During Rim of the Pacific naval exercises in July, environmentalists settled a lawsuit over active sonar use after the Navy agreed to increased safeguards for marine mammals.

The upcoming environmental impact statement will address marine-mammal impact. Additional challenges to sonar use also are expected.

The Navy, on a Web site created to address sonar and environmental issues at www.govsupport.us/navynepahawaii/default.aspx, said it recognizes that active sonar can affect marine mammals.

As a result, protective measures are now standard, including posting lookouts who search with binoculars for marine animals, and delaying or moving sonar activity or reducing sonar power if animals are detected.

The Navy said diesel submarines are designed to operate quietly, and passive or listening sonar provides only a general bearing on a target. For that reason, it cannot be used to target enemy ships.

Reach William Cole at wcole@honoluluadvertiser.com.